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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    <a name="line.17"></a>
<FONT color="green">018</FONT>    package org.apache.commons.math3.analysis.solvers;<a name="line.18"></a>
<FONT color="green">019</FONT>    <a name="line.19"></a>
<FONT color="green">020</FONT>    import org.apache.commons.math3.util.FastMath;<a name="line.20"></a>
<FONT color="green">021</FONT>    import org.apache.commons.math3.analysis.UnivariateFunction;<a name="line.21"></a>
<FONT color="green">022</FONT>    import org.apache.commons.math3.exception.ConvergenceException;<a name="line.22"></a>
<FONT color="green">023</FONT>    import org.apache.commons.math3.exception.MathInternalError;<a name="line.23"></a>
<FONT color="green">024</FONT>    <a name="line.24"></a>
<FONT color="green">025</FONT>    /**<a name="line.25"></a>
<FONT color="green">026</FONT>     * Base class for all bracketing &lt;em&gt;Secant&lt;/em&gt;-based methods for root-finding<a name="line.26"></a>
<FONT color="green">027</FONT>     * (approximating a zero of a univariate real function).<a name="line.27"></a>
<FONT color="green">028</FONT>     *<a name="line.28"></a>
<FONT color="green">029</FONT>     * &lt;p&gt;Implementation of the {@link RegulaFalsiSolver &lt;em&gt;Regula Falsi&lt;/em&gt;} and<a name="line.29"></a>
<FONT color="green">030</FONT>     * {@link IllinoisSolver &lt;em&gt;Illinois&lt;/em&gt;} methods is based on the<a name="line.30"></a>
<FONT color="green">031</FONT>     * following article: M. Dowell and P. Jarratt,<a name="line.31"></a>
<FONT color="green">032</FONT>     * &lt;em&gt;A modified regula falsi method for computing the root of an<a name="line.32"></a>
<FONT color="green">033</FONT>     * equation&lt;/em&gt;, BIT Numerical Mathematics, volume 11, number 2,<a name="line.33"></a>
<FONT color="green">034</FONT>     * pages 168-174, Springer, 1971.&lt;/p&gt;<a name="line.34"></a>
<FONT color="green">035</FONT>     *<a name="line.35"></a>
<FONT color="green">036</FONT>     * &lt;p&gt;Implementation of the {@link PegasusSolver &lt;em&gt;Pegasus&lt;/em&gt;} method is<a name="line.36"></a>
<FONT color="green">037</FONT>     * based on the following article: M. Dowell and P. Jarratt,<a name="line.37"></a>
<FONT color="green">038</FONT>     * &lt;em&gt;The "Pegasus" method for computing the root of an equation&lt;/em&gt;,<a name="line.38"></a>
<FONT color="green">039</FONT>     * BIT Numerical Mathematics, volume 12, number 4, pages 503-508, Springer,<a name="line.39"></a>
<FONT color="green">040</FONT>     * 1972.&lt;/p&gt;<a name="line.40"></a>
<FONT color="green">041</FONT>     *<a name="line.41"></a>
<FONT color="green">042</FONT>     * &lt;p&gt;The {@link SecantSolver &lt;em&gt;Secant&lt;/em&gt;} method is &lt;em&gt;not&lt;/em&gt; a<a name="line.42"></a>
<FONT color="green">043</FONT>     * bracketing method, so it is not implemented here. It has a separate<a name="line.43"></a>
<FONT color="green">044</FONT>     * implementation.&lt;/p&gt;<a name="line.44"></a>
<FONT color="green">045</FONT>     *<a name="line.45"></a>
<FONT color="green">046</FONT>     * @since 3.0<a name="line.46"></a>
<FONT color="green">047</FONT>     * @version $Id: BaseSecantSolver.java 1379560 2012-08-31 19:40:30Z erans $<a name="line.47"></a>
<FONT color="green">048</FONT>     */<a name="line.48"></a>
<FONT color="green">049</FONT>    public abstract class BaseSecantSolver<a name="line.49"></a>
<FONT color="green">050</FONT>        extends AbstractUnivariateSolver<a name="line.50"></a>
<FONT color="green">051</FONT>        implements BracketedUnivariateSolver&lt;UnivariateFunction&gt; {<a name="line.51"></a>
<FONT color="green">052</FONT>    <a name="line.52"></a>
<FONT color="green">053</FONT>        /** Default absolute accuracy. */<a name="line.53"></a>
<FONT color="green">054</FONT>        protected static final double DEFAULT_ABSOLUTE_ACCURACY = 1e-6;<a name="line.54"></a>
<FONT color="green">055</FONT>    <a name="line.55"></a>
<FONT color="green">056</FONT>        /** The kinds of solutions that the algorithm may accept. */<a name="line.56"></a>
<FONT color="green">057</FONT>        private AllowedSolution allowed;<a name="line.57"></a>
<FONT color="green">058</FONT>    <a name="line.58"></a>
<FONT color="green">059</FONT>        /** The &lt;em&gt;Secant&lt;/em&gt;-based root-finding method to use. */<a name="line.59"></a>
<FONT color="green">060</FONT>        private final Method method;<a name="line.60"></a>
<FONT color="green">061</FONT>    <a name="line.61"></a>
<FONT color="green">062</FONT>        /**<a name="line.62"></a>
<FONT color="green">063</FONT>         * Construct a solver.<a name="line.63"></a>
<FONT color="green">064</FONT>         *<a name="line.64"></a>
<FONT color="green">065</FONT>         * @param absoluteAccuracy Absolute accuracy.<a name="line.65"></a>
<FONT color="green">066</FONT>         * @param method &lt;em&gt;Secant&lt;/em&gt;-based root-finding method to use.<a name="line.66"></a>
<FONT color="green">067</FONT>         */<a name="line.67"></a>
<FONT color="green">068</FONT>        protected BaseSecantSolver(final double absoluteAccuracy, final Method method) {<a name="line.68"></a>
<FONT color="green">069</FONT>            super(absoluteAccuracy);<a name="line.69"></a>
<FONT color="green">070</FONT>            this.allowed = AllowedSolution.ANY_SIDE;<a name="line.70"></a>
<FONT color="green">071</FONT>            this.method = method;<a name="line.71"></a>
<FONT color="green">072</FONT>        }<a name="line.72"></a>
<FONT color="green">073</FONT>    <a name="line.73"></a>
<FONT color="green">074</FONT>        /**<a name="line.74"></a>
<FONT color="green">075</FONT>         * Construct a solver.<a name="line.75"></a>
<FONT color="green">076</FONT>         *<a name="line.76"></a>
<FONT color="green">077</FONT>         * @param relativeAccuracy Relative accuracy.<a name="line.77"></a>
<FONT color="green">078</FONT>         * @param absoluteAccuracy Absolute accuracy.<a name="line.78"></a>
<FONT color="green">079</FONT>         * @param method &lt;em&gt;Secant&lt;/em&gt;-based root-finding method to use.<a name="line.79"></a>
<FONT color="green">080</FONT>         */<a name="line.80"></a>
<FONT color="green">081</FONT>        protected BaseSecantSolver(final double relativeAccuracy,<a name="line.81"></a>
<FONT color="green">082</FONT>                                   final double absoluteAccuracy,<a name="line.82"></a>
<FONT color="green">083</FONT>                                   final Method method) {<a name="line.83"></a>
<FONT color="green">084</FONT>            super(relativeAccuracy, absoluteAccuracy);<a name="line.84"></a>
<FONT color="green">085</FONT>            this.allowed = AllowedSolution.ANY_SIDE;<a name="line.85"></a>
<FONT color="green">086</FONT>            this.method = method;<a name="line.86"></a>
<FONT color="green">087</FONT>        }<a name="line.87"></a>
<FONT color="green">088</FONT>    <a name="line.88"></a>
<FONT color="green">089</FONT>        /**<a name="line.89"></a>
<FONT color="green">090</FONT>         * Construct a solver.<a name="line.90"></a>
<FONT color="green">091</FONT>         *<a name="line.91"></a>
<FONT color="green">092</FONT>         * @param relativeAccuracy Maximum relative error.<a name="line.92"></a>
<FONT color="green">093</FONT>         * @param absoluteAccuracy Maximum absolute error.<a name="line.93"></a>
<FONT color="green">094</FONT>         * @param functionValueAccuracy Maximum function value error.<a name="line.94"></a>
<FONT color="green">095</FONT>         * @param method &lt;em&gt;Secant&lt;/em&gt;-based root-finding method to use<a name="line.95"></a>
<FONT color="green">096</FONT>         */<a name="line.96"></a>
<FONT color="green">097</FONT>        protected BaseSecantSolver(final double relativeAccuracy,<a name="line.97"></a>
<FONT color="green">098</FONT>                                   final double absoluteAccuracy,<a name="line.98"></a>
<FONT color="green">099</FONT>                                   final double functionValueAccuracy,<a name="line.99"></a>
<FONT color="green">100</FONT>                                   final Method method) {<a name="line.100"></a>
<FONT color="green">101</FONT>            super(relativeAccuracy, absoluteAccuracy, functionValueAccuracy);<a name="line.101"></a>
<FONT color="green">102</FONT>            this.allowed = AllowedSolution.ANY_SIDE;<a name="line.102"></a>
<FONT color="green">103</FONT>            this.method = method;<a name="line.103"></a>
<FONT color="green">104</FONT>        }<a name="line.104"></a>
<FONT color="green">105</FONT>    <a name="line.105"></a>
<FONT color="green">106</FONT>        /** {@inheritDoc} */<a name="line.106"></a>
<FONT color="green">107</FONT>        public double solve(final int maxEval, final UnivariateFunction f,<a name="line.107"></a>
<FONT color="green">108</FONT>                            final double min, final double max,<a name="line.108"></a>
<FONT color="green">109</FONT>                            final AllowedSolution allowedSolution) {<a name="line.109"></a>
<FONT color="green">110</FONT>            return solve(maxEval, f, min, max, min + 0.5 * (max - min), allowedSolution);<a name="line.110"></a>
<FONT color="green">111</FONT>        }<a name="line.111"></a>
<FONT color="green">112</FONT>    <a name="line.112"></a>
<FONT color="green">113</FONT>        /** {@inheritDoc} */<a name="line.113"></a>
<FONT color="green">114</FONT>        public double solve(final int maxEval, final UnivariateFunction f,<a name="line.114"></a>
<FONT color="green">115</FONT>                            final double min, final double max, final double startValue,<a name="line.115"></a>
<FONT color="green">116</FONT>                            final AllowedSolution allowedSolution) {<a name="line.116"></a>
<FONT color="green">117</FONT>            this.allowed = allowedSolution;<a name="line.117"></a>
<FONT color="green">118</FONT>            return super.solve(maxEval, f, min, max, startValue);<a name="line.118"></a>
<FONT color="green">119</FONT>        }<a name="line.119"></a>
<FONT color="green">120</FONT>    <a name="line.120"></a>
<FONT color="green">121</FONT>        /** {@inheritDoc} */<a name="line.121"></a>
<FONT color="green">122</FONT>        @Override<a name="line.122"></a>
<FONT color="green">123</FONT>        public double solve(final int maxEval, final UnivariateFunction f,<a name="line.123"></a>
<FONT color="green">124</FONT>                            final double min, final double max, final double startValue) {<a name="line.124"></a>
<FONT color="green">125</FONT>            return solve(maxEval, f, min, max, startValue, AllowedSolution.ANY_SIDE);<a name="line.125"></a>
<FONT color="green">126</FONT>        }<a name="line.126"></a>
<FONT color="green">127</FONT>    <a name="line.127"></a>
<FONT color="green">128</FONT>        /**<a name="line.128"></a>
<FONT color="green">129</FONT>         * {@inheritDoc}<a name="line.129"></a>
<FONT color="green">130</FONT>         *<a name="line.130"></a>
<FONT color="green">131</FONT>         * @throws ConvergenceException if the algorithm failed due to finite<a name="line.131"></a>
<FONT color="green">132</FONT>         * precision.<a name="line.132"></a>
<FONT color="green">133</FONT>         */<a name="line.133"></a>
<FONT color="green">134</FONT>        @Override<a name="line.134"></a>
<FONT color="green">135</FONT>        protected final double doSolve()<a name="line.135"></a>
<FONT color="green">136</FONT>            throws ConvergenceException,<a name="line.136"></a>
<FONT color="green">137</FONT>                   MathInternalError {<a name="line.137"></a>
<FONT color="green">138</FONT>            // Get initial solution<a name="line.138"></a>
<FONT color="green">139</FONT>            double x0 = getMin();<a name="line.139"></a>
<FONT color="green">140</FONT>            double x1 = getMax();<a name="line.140"></a>
<FONT color="green">141</FONT>            double f0 = computeObjectiveValue(x0);<a name="line.141"></a>
<FONT color="green">142</FONT>            double f1 = computeObjectiveValue(x1);<a name="line.142"></a>
<FONT color="green">143</FONT>    <a name="line.143"></a>
<FONT color="green">144</FONT>            // If one of the bounds is the exact root, return it. Since these are<a name="line.144"></a>
<FONT color="green">145</FONT>            // not under-approximations or over-approximations, we can return them<a name="line.145"></a>
<FONT color="green">146</FONT>            // regardless of the allowed solutions.<a name="line.146"></a>
<FONT color="green">147</FONT>            if (f0 == 0.0) {<a name="line.147"></a>
<FONT color="green">148</FONT>                return x0;<a name="line.148"></a>
<FONT color="green">149</FONT>            }<a name="line.149"></a>
<FONT color="green">150</FONT>            if (f1 == 0.0) {<a name="line.150"></a>
<FONT color="green">151</FONT>                return x1;<a name="line.151"></a>
<FONT color="green">152</FONT>            }<a name="line.152"></a>
<FONT color="green">153</FONT>    <a name="line.153"></a>
<FONT color="green">154</FONT>            // Verify bracketing of initial solution.<a name="line.154"></a>
<FONT color="green">155</FONT>            verifyBracketing(x0, x1);<a name="line.155"></a>
<FONT color="green">156</FONT>    <a name="line.156"></a>
<FONT color="green">157</FONT>            // Get accuracies.<a name="line.157"></a>
<FONT color="green">158</FONT>            final double ftol = getFunctionValueAccuracy();<a name="line.158"></a>
<FONT color="green">159</FONT>            final double atol = getAbsoluteAccuracy();<a name="line.159"></a>
<FONT color="green">160</FONT>            final double rtol = getRelativeAccuracy();<a name="line.160"></a>
<FONT color="green">161</FONT>    <a name="line.161"></a>
<FONT color="green">162</FONT>            // Keep track of inverted intervals, meaning that the left bound is<a name="line.162"></a>
<FONT color="green">163</FONT>            // larger than the right bound.<a name="line.163"></a>
<FONT color="green">164</FONT>            boolean inverted = false;<a name="line.164"></a>
<FONT color="green">165</FONT>    <a name="line.165"></a>
<FONT color="green">166</FONT>            // Keep finding better approximations.<a name="line.166"></a>
<FONT color="green">167</FONT>            while (true) {<a name="line.167"></a>
<FONT color="green">168</FONT>                // Calculate the next approximation.<a name="line.168"></a>
<FONT color="green">169</FONT>                final double x = x1 - ((f1 * (x1 - x0)) / (f1 - f0));<a name="line.169"></a>
<FONT color="green">170</FONT>                final double fx = computeObjectiveValue(x);<a name="line.170"></a>
<FONT color="green">171</FONT>    <a name="line.171"></a>
<FONT color="green">172</FONT>                // If the new approximation is the exact root, return it. Since<a name="line.172"></a>
<FONT color="green">173</FONT>                // this is not an under-approximation or an over-approximation,<a name="line.173"></a>
<FONT color="green">174</FONT>                // we can return it regardless of the allowed solutions.<a name="line.174"></a>
<FONT color="green">175</FONT>                if (fx == 0.0) {<a name="line.175"></a>
<FONT color="green">176</FONT>                    return x;<a name="line.176"></a>
<FONT color="green">177</FONT>                }<a name="line.177"></a>
<FONT color="green">178</FONT>    <a name="line.178"></a>
<FONT color="green">179</FONT>                // Update the bounds with the new approximation.<a name="line.179"></a>
<FONT color="green">180</FONT>                if (f1 * fx &lt; 0) {<a name="line.180"></a>
<FONT color="green">181</FONT>                    // The value of x1 has switched to the other bound, thus inverting<a name="line.181"></a>
<FONT color="green">182</FONT>                    // the interval.<a name="line.182"></a>
<FONT color="green">183</FONT>                    x0 = x1;<a name="line.183"></a>
<FONT color="green">184</FONT>                    f0 = f1;<a name="line.184"></a>
<FONT color="green">185</FONT>                    inverted = !inverted;<a name="line.185"></a>
<FONT color="green">186</FONT>                } else {<a name="line.186"></a>
<FONT color="green">187</FONT>                    switch (method) {<a name="line.187"></a>
<FONT color="green">188</FONT>                    case ILLINOIS:<a name="line.188"></a>
<FONT color="green">189</FONT>                        f0 *= 0.5;<a name="line.189"></a>
<FONT color="green">190</FONT>                        break;<a name="line.190"></a>
<FONT color="green">191</FONT>                    case PEGASUS:<a name="line.191"></a>
<FONT color="green">192</FONT>                        f0 *= f1 / (f1 + fx);<a name="line.192"></a>
<FONT color="green">193</FONT>                        break;<a name="line.193"></a>
<FONT color="green">194</FONT>                    case REGULA_FALSI:<a name="line.194"></a>
<FONT color="green">195</FONT>                        // Detect early that algorithm is stuck, instead of waiting<a name="line.195"></a>
<FONT color="green">196</FONT>                        // for the maximum number of iterations to be exceeded.<a name="line.196"></a>
<FONT color="green">197</FONT>                        if (x == x1) {<a name="line.197"></a>
<FONT color="green">198</FONT>                            throw new ConvergenceException();<a name="line.198"></a>
<FONT color="green">199</FONT>                        }<a name="line.199"></a>
<FONT color="green">200</FONT>                        break;<a name="line.200"></a>
<FONT color="green">201</FONT>                    default:<a name="line.201"></a>
<FONT color="green">202</FONT>                        // Should never happen.<a name="line.202"></a>
<FONT color="green">203</FONT>                        throw new MathInternalError();<a name="line.203"></a>
<FONT color="green">204</FONT>                    }<a name="line.204"></a>
<FONT color="green">205</FONT>                }<a name="line.205"></a>
<FONT color="green">206</FONT>                // Update from [x0, x1] to [x0, x].<a name="line.206"></a>
<FONT color="green">207</FONT>                x1 = x;<a name="line.207"></a>
<FONT color="green">208</FONT>                f1 = fx;<a name="line.208"></a>
<FONT color="green">209</FONT>    <a name="line.209"></a>
<FONT color="green">210</FONT>                // If the function value of the last approximation is too small,<a name="line.210"></a>
<FONT color="green">211</FONT>                // given the function value accuracy, then we can't get closer to<a name="line.211"></a>
<FONT color="green">212</FONT>                // the root than we already are.<a name="line.212"></a>
<FONT color="green">213</FONT>                if (FastMath.abs(f1) &lt;= ftol) {<a name="line.213"></a>
<FONT color="green">214</FONT>                    switch (allowed) {<a name="line.214"></a>
<FONT color="green">215</FONT>                    case ANY_SIDE:<a name="line.215"></a>
<FONT color="green">216</FONT>                        return x1;<a name="line.216"></a>
<FONT color="green">217</FONT>                    case LEFT_SIDE:<a name="line.217"></a>
<FONT color="green">218</FONT>                        if (inverted) {<a name="line.218"></a>
<FONT color="green">219</FONT>                            return x1;<a name="line.219"></a>
<FONT color="green">220</FONT>                        }<a name="line.220"></a>
<FONT color="green">221</FONT>                        break;<a name="line.221"></a>
<FONT color="green">222</FONT>                    case RIGHT_SIDE:<a name="line.222"></a>
<FONT color="green">223</FONT>                        if (!inverted) {<a name="line.223"></a>
<FONT color="green">224</FONT>                            return x1;<a name="line.224"></a>
<FONT color="green">225</FONT>                        }<a name="line.225"></a>
<FONT color="green">226</FONT>                        break;<a name="line.226"></a>
<FONT color="green">227</FONT>                    case BELOW_SIDE:<a name="line.227"></a>
<FONT color="green">228</FONT>                        if (f1 &lt;= 0) {<a name="line.228"></a>
<FONT color="green">229</FONT>                            return x1;<a name="line.229"></a>
<FONT color="green">230</FONT>                        }<a name="line.230"></a>
<FONT color="green">231</FONT>                        break;<a name="line.231"></a>
<FONT color="green">232</FONT>                    case ABOVE_SIDE:<a name="line.232"></a>
<FONT color="green">233</FONT>                        if (f1 &gt;= 0) {<a name="line.233"></a>
<FONT color="green">234</FONT>                            return x1;<a name="line.234"></a>
<FONT color="green">235</FONT>                        }<a name="line.235"></a>
<FONT color="green">236</FONT>                        break;<a name="line.236"></a>
<FONT color="green">237</FONT>                    default:<a name="line.237"></a>
<FONT color="green">238</FONT>                        throw new MathInternalError();<a name="line.238"></a>
<FONT color="green">239</FONT>                    }<a name="line.239"></a>
<FONT color="green">240</FONT>                }<a name="line.240"></a>
<FONT color="green">241</FONT>    <a name="line.241"></a>
<FONT color="green">242</FONT>                // If the current interval is within the given accuracies, we<a name="line.242"></a>
<FONT color="green">243</FONT>                // are satisfied with the current approximation.<a name="line.243"></a>
<FONT color="green">244</FONT>                if (FastMath.abs(x1 - x0) &lt; FastMath.max(rtol * FastMath.abs(x1),<a name="line.244"></a>
<FONT color="green">245</FONT>                                                         atol)) {<a name="line.245"></a>
<FONT color="green">246</FONT>                    switch (allowed) {<a name="line.246"></a>
<FONT color="green">247</FONT>                    case ANY_SIDE:<a name="line.247"></a>
<FONT color="green">248</FONT>                        return x1;<a name="line.248"></a>
<FONT color="green">249</FONT>                    case LEFT_SIDE:<a name="line.249"></a>
<FONT color="green">250</FONT>                        return inverted ? x1 : x0;<a name="line.250"></a>
<FONT color="green">251</FONT>                    case RIGHT_SIDE:<a name="line.251"></a>
<FONT color="green">252</FONT>                        return inverted ? x0 : x1;<a name="line.252"></a>
<FONT color="green">253</FONT>                    case BELOW_SIDE:<a name="line.253"></a>
<FONT color="green">254</FONT>                        return (f1 &lt;= 0) ? x1 : x0;<a name="line.254"></a>
<FONT color="green">255</FONT>                    case ABOVE_SIDE:<a name="line.255"></a>
<FONT color="green">256</FONT>                        return (f1 &gt;= 0) ? x1 : x0;<a name="line.256"></a>
<FONT color="green">257</FONT>                    default:<a name="line.257"></a>
<FONT color="green">258</FONT>                        throw new MathInternalError();<a name="line.258"></a>
<FONT color="green">259</FONT>                    }<a name="line.259"></a>
<FONT color="green">260</FONT>                }<a name="line.260"></a>
<FONT color="green">261</FONT>            }<a name="line.261"></a>
<FONT color="green">262</FONT>        }<a name="line.262"></a>
<FONT color="green">263</FONT>    <a name="line.263"></a>
<FONT color="green">264</FONT>        /** &lt;em&gt;Secant&lt;/em&gt;-based root-finding methods. */<a name="line.264"></a>
<FONT color="green">265</FONT>        protected enum Method {<a name="line.265"></a>
<FONT color="green">266</FONT>    <a name="line.266"></a>
<FONT color="green">267</FONT>            /**<a name="line.267"></a>
<FONT color="green">268</FONT>             * The {@link RegulaFalsiSolver &lt;em&gt;Regula Falsi&lt;/em&gt;} or<a name="line.268"></a>
<FONT color="green">269</FONT>             * &lt;em&gt;False Position&lt;/em&gt; method.<a name="line.269"></a>
<FONT color="green">270</FONT>             */<a name="line.270"></a>
<FONT color="green">271</FONT>            REGULA_FALSI,<a name="line.271"></a>
<FONT color="green">272</FONT>    <a name="line.272"></a>
<FONT color="green">273</FONT>            /** The {@link IllinoisSolver &lt;em&gt;Illinois&lt;/em&gt;} method. */<a name="line.273"></a>
<FONT color="green">274</FONT>            ILLINOIS,<a name="line.274"></a>
<FONT color="green">275</FONT>    <a name="line.275"></a>
<FONT color="green">276</FONT>            /** The {@link PegasusSolver &lt;em&gt;Pegasus&lt;/em&gt;} method. */<a name="line.276"></a>
<FONT color="green">277</FONT>            PEGASUS;<a name="line.277"></a>
<FONT color="green">278</FONT>    <a name="line.278"></a>
<FONT color="green">279</FONT>        }<a name="line.279"></a>
<FONT color="green">280</FONT>    }<a name="line.280"></a>




























































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